U.S. patent application number 17/439878 was filed with the patent office on 2022-06-16 for method for preparing a pultruded polyurethane composite.
The applicant listed for this patent is Covestro Intellectual Property GmbH & Co. KG. Invention is credited to Yongming Gu, Christian Kube, Zhijiang Li, Guobin Sun, Hui Zhang.
Application Number | 20220184901 17/439878 |
Document ID | / |
Family ID | |
Filed Date | 2022-06-16 |
United States Patent
Application |
20220184901 |
Kind Code |
A1 |
Li; Zhijiang ; et
al. |
June 16, 2022 |
METHOD FOR PREPARING A PULTRUDED POLYURETHANE COMPOSITE
Abstract
The present invention relates to a method for preparing a
pultruded polyurethane composite by a polyurethane pultrusion
process, a pultruded polyurethane composite prepared by said
method, and uses thereof. The method for preparing a pultruded
polyurethane composite of the present invention employs short
molds, improves production efficiency and saves costs.
Inventors: |
Li; Zhijiang; (Pudong
District, Shanghai, CN) ; Gu; Yongming; (Pudong New
District, Shanghai, CN) ; Sun; Guobin; (Pudong,
Shanghai, CN) ; Zhang; Hui; (Zhujing Town, Jinshan
District, Shanghai, CN) ; Kube; Christian; (Siegburg,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Covestro Intellectual Property GmbH & Co. KG |
Leverkusen |
|
DE |
|
|
Appl. No.: |
17/439878 |
Filed: |
March 20, 2020 |
PCT Filed: |
March 20, 2020 |
PCT NO: |
PCT/EP2020/057752 |
371 Date: |
September 16, 2021 |
International
Class: |
B29C 70/52 20060101
B29C070/52; C08J 5/24 20060101 C08J005/24; C08G 18/12 20060101
C08G018/12; C08G 18/75 20060101 C08G018/75; C08G 18/76 20060101
C08G018/76; C08G 18/67 20060101 C08G018/67; C08G 18/44 20060101
C08G018/44; C08G 18/48 20060101 C08G018/48 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 26, 2019 |
CN |
201910235171.5 |
May 2, 2019 |
EP |
19172172.9 |
Claims
1. A method for preparing a pultruded polyurethane composite by a
polyurethane pultrusion process, comprising: impregnating a fiber
reinforcing material with a polyurethane composition comprising: a
component A, including one or more organic polyisocyanates; a
component B, including: b1) one or more organic polyols in an
amount of 21 to 60 wt %, based on the total weight of the
polyurethane composition as 100 wt %; b2) one or more compounds
having a structure of formula (I) ##STR00006## wherein R.sub.1 is
selected from the group consisting of hydrogen, methyl or ethyl; R2
is selected from the group consisting of an alkylene group having 2
to 6 carbon atoms, 2,2-di(4-phenylene)-propane,
1,4-di(methylene)benzene, 1,3-di(methylene)benzene,
1,2-di(methylene)benzene; and n is an integer selected from 1 to 6;
and a component C, free radical initiator; drawing the impregnated
fiber reinforcing material at a speed of 0.2 to 2 m/min through a
mold having a length of 21 to 55 cm and a controlled temperature of
110 to 230.degree. C. to form the pultruded polyurethane
composite.
2. The method as claimed in claim 1, wherein the component b2) is
selected from the group consisting of hydroxyethyl methacrylate,
hydroxypropyl methacrylate, hydroxybutyl methacrylate, hydroxyethyl
acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate ora
combination thereof.
3. The method as claimed in claim 1, wherein b2) is present in an
amount of 4.6 to 33 wt %, based on the total weight of the
polyurethane composition as 100 wt %.
4. The method as claimed in claim 1, wherein the fiber reinforcing
material is selected from the group consisting of glass fiber,
carbon fiber, polyester fiber, natural fiber, aramid fiber, nylon
fiber, basalt fiber, boron fiber, silicon carbide fiber, asbestos
fiber, whisker, hard particle, metal fiber or a combination
thereof.
5. The method as claimed in claim 1, wherein the polyurethane
composition has a curing time of 10 to 120 seconds at 150 to
220.degree. C.
6. The method as claimed in claim 1, wherein the polyurethane
composition has a gel time of 15 to 90 minutes at room
temperature.
7. The method as claimed in claim 1, wherein said impregnating is
carried out in an impregnation device comprising an injection box
and an open impregnation tank.
8. The method as claimed in claim 7, wherein the injection pressure
in the injection box is 0.1 to 15 bar.
9. A pultruded polyurethane composite obtained by the method as
claimed in claim 1.
10. (canceled)
11. The pultruded polyurethane composite as claimed in claim 9,
wherein b2) is present in an amount of 4.6 to 33 wt %, based on the
total weight of the polyurethane composition as 100 wt %.
12. The pultruded polyurethane composite as claimed in claim 9,
wherein the polyurethane composition has a curing time of 10 to 120
seconds.
13. The pultruded polyurethane composite as claimed in claim 9,
wherein the polyurethane composition has a gel time of 15 to 90
minutes.
14. A polyurethane product comprising the pultruded polyurethane
composite as claimed in claim 9.
15. The polyurethane product as claimed in claim 14, wherein the
polyurethane product is selected from the group consisting of a
cable tray, a curtain wall frame, a ladder frame, a tent pole or
tube, an anti-glare panel, a floor, a sucker rod, an electric pole,
an electric crossarm, a guardrail, a grid, a profile for
construction, a profile or plate for container, a bicycle frame, a
fishing rod, a cable core, an insulator core rod, a radome, a
single or sandwich continuous plate, or a spar cap for a wind
turbine blade.
Description
TECHNICAL FIELD
[0001] The present invention relates to the field of polyurethane
pultrusion process. In particular, the present invention relates to
a method for preparing a pultruded polyurethane composite by a
polyurethane pultrusion process, a pultruded polyurethane composite
prepared by said method, and uses thereof.
PRIOR ART
[0002] Pultruded composites have characteristics such as high fiber
content and uniform quality, and are well concerned in the
industry. The pultrusion process is simple and efficient, can be
used continuously and thus is widely applied. A general specific
operation mode of the pultrusion process is as follows. Fiber yarns
or fiber fabrics are continuously taken out from a creel, and are
impregnated with a resin by an open impregnation tank or a closed
injection box. After the fibers are impregnated with the resin,
they are fed into a mold which maintains a certain cross-sectional
shape for thermal curing. Then the fibers are continuously pulled
out of the mold by a drawing device. Finally they are cut into the
required length in-line to obtain a corresponding composite.
[0003] Typically, the existing pultrusion processes employ
relatively long curing molds of typically 90 to 100 cm, or even
longer. Relatively long molds are heavier, and too bulky especially
for larger articles, which may lead to very long time for
production preparations such as mold maintenance, threading and
heating. At the same time, because the molds are relatively long
and bulky, the energy consumption during heating is very high. So
it is unfavorable for energy conservation, emission reduction and
environment protection.
[0004] CN101341018B discloses a system (100) for producing a
pultruded component (50). The system includes an impregnation die
(150) for wetting yarns (110) of fiber with a polymeric resin
precursor (141). The impregnation die (150) includes a first
chamber (154) for coating external surfaces of the yarns (110) and
a second chamber (156) for coating fibers within the yarns (110).
The second chamber (156) has a cross-sectional area that decreases
between an entrance to the second chamber (156) and an exit from
the second chamber (156). The system (100) also includes a member
(151) for spacing the yarns (110) apart prior to entering the first
chamber (154) to allow the polymeric resin precursor (141) to flow
around the external surfaces of the yarns (110).
[0005] CN106626445A discloses an integrated injection mold for
polyurethane pultrusion and a method for utilizing the same. The
integrated injection mold comprises a mold main body. The mold main
body comprises a lower mold and an upper mold. Electric heating
sheets are fixed to the left end of the mold main body, a material
injection opening is formed on the top surface of the mold main
body. A base plate, a supporting strip, a right end feeding
supporting plate and a middle supporting plate are fixed to the
right end of the mold main body. After the mold is erected, the two
electric heating sheets start heating. Felt cloth is fed to the
middle supporting plate through an feeding hole for inner-layer
felt cloth. Glass fiber filaments are guided to the middle
supporting plate through an inlet hole for glass fiber filaments.
Then outer-layer felt cloth is guided to the middle supporting
plate through a feeding hole for outer-layer felt cloth, which is
in the periphery of the inlet hole for glass fiber filaments.
During the forward movement, a polyurethane matrix starts to be
injected through the material injection opening. In order to avoid
coagulation by heat of the polyurethane matrix, a cooling zone is
especially arranged on the left side of the material injection
opening. After the resin matrix, the felt cloth and glass fiber
bundles are fully bonded, coagulation by warming is conducted at
the left end of the mold main body.
[0006] CN101312999B discloses a resin precursor composition for
producing composite components. The composition comprises an
isocyanate component comprising a material selected from the group
consisting of diphenylmethane diisocyanate, a polymeric isomer of
diphenylmethane diisocyanate, and mixtures thereof. The resin
precursor composition also comprises at least one polyether polyol
having a functionality of 3 in such an amount that the
stoichiometric ratio of the isocyanate component to the at least
one polyether polyol is between approximately 80% and 115%. The
resin precursor composition also comprises a mold releasing
material and a filler.
[0007] WO 2018/097874 A1 discloses a polyurethane composite
produced by a conventional process including impregnating fibers
with a urethane acrylate resin in a bath and curing for several
hours. There is no pultrusion process disclosed.
[0008] WO 2018/219756 A1 discloses a polyurethane reaction
composition for conventional production of a polyurethane acrylate
composite. There is no pultrusion process disclosed.
[0009] US 2002/045690 A1 discloses a polyurethane reaction mixture
for pultrusion processes. The reaction mixture does not contain
acrylates, die lengths are typically in the conventional range of
about 100 cm, and indices of the reaction mixtures are typically in
the range of 250 or above.
[0010] Despite the above disclosures, there is an urgent need for
improved methods and molds to improve production efficiency and to
meet the requirements of energy conservation, emission reduction
and environment protection.
SUMMARY OF THE INVENTION
[0011] One aspect of the present invention provides a method for
preparing a pultruded polyurethane composite by a polyurethane
pultrusion process, comprising the steps of:
[0012] impregnating a fiber reinforcing material with a
polyurethane composition comprising the following components:
[0013] a component A, including one or more organic
polyisocyanates; [0014] a component B, including: [0015] b1) one or
more organic polyols in an amount of 21 to 60 wt %, preferably 21
to 40 wt %, based on the total weight of the polyurethane
composition as 100 wt %; [0016] b2) one or more compounds having a
structure of formula (I)
[0016] ##STR00001## wherein R1 is selected from the group
consisting of hydrogen, methyl or ethyl; R2 is selected from the
group consisting of an alkylene group having 2 to 6 carbon atoms,
2,2-di(4-phenylene)-propane, 1,4-di(methylene)benzene,
1,3-di(methylene)benzene, 1,2-di(methylene)benzene; n is an integer
selected from 1 to 6; and [0017] a component C, free radical
initiator; drawing the impregnated fiber reinforcing material at a
speed of 0.2 to 2 m/min, preferably 0.4 to 1.5 m/min through a mold
having a length of 21 to 55 cm, preferably 25 to 55 cm, more
preferably 30 to 50 cm or 21 to 40 cm and a controlled temperature
of 110 to 230.degree. C., preferably 150 to 220.degree. C., curing
to form the pultruded polyurethane composite.
[0018] Preferably, the polyurethane resin is prepared under a
reaction condition in which the polyurethane composition is
simultaneously subjected to a free radical polymerization reaction
and a polyaddition reaction of isocyanate groups and hydroxyl
groups.
[0019] Preferably, b1) is selected from the group consisting of
organic polyols, wherein said organic polyols have a functionality
of 1.7 to 6, preferably 1.9 to 4.5 and a hydroxyl value of 150 to
1100 mg KOH/g, preferably 150 to 550 mg KOH/g.
[0020] Preferably, the component b2) is selected from the group
consisting of hydroxyethyl methacrylate, hydroxypropyl
methacrylate, hydroxybutyl methacrylate, hydroxyethyl acrylate,
hydroxypropyl acrylate, hydroxybutyl acrylate or combinations
thereof. Preferably, b2) is present in an amount of 4.6 to 33 wt %,
based on the total weight of the polyurethane composition as 100 wt
%.
[0021] Preferably, the fiber reinforcing material is selected from
the group consisting of glass fiber, carbon fiber, polyester fiber,
natural fiber, aramid fiber, nylon fiber, basalt fiber, boron
fiber, silicon carbide fiber, asbestos fiber, whisker, hard
particle, metal fiber or combinations thereof.
[0022] Preferably, the free radical initiator used in the present
invention may be added to the polyol component or the isocyanate
component, or separately added to the aforementioned two
components. The free radical initiator includes, but is not limited
to, a peroxide, a persulfide, a peroxycarbonate, a peroxyboric
acid, an azo compound, or other suitable free radical initiators
that can initiate curing of double bond-containing compounds.
Examples thereof include tert-butyl peroxy-isopropylcarbonate,
tert-butyl peroxy-3,5,5-trimethylhexanoate, methyl ethyl ketone
peroxide, and cumyl hydroperoxide.
[0023] Preferably, the polyurethane composition has a curing time
of 10 to 120 seconds, preferably 15 to 90 seconds, at 150 to
220.degree. C.
[0024] Preferably, the polyurethane composition has a gel time of
15 to 90 minutes, preferably 20 to 60 minutes, at room
temperature.
[0025] Preferably, the impregnating is carried out in an
impregnation device comprising an injection box and an open
impregnation tank.
[0026] Preferably, the injection pressure in the injection box is
0.1 to 15 bar, preferably 0.1 to 10 bar.
[0027] It is well known to those skilled in the art that the molds
for polyurethane compositions (without component b2) of the present
invention and the component free radical initiator) which is
conventionally used in the pultrusion process in the prior art has
a length generally from 90 to 100 cm. The mold of the present
invention can be shortened by 45% to 76.7%, preferably 45% to
72.2%, more preferably 50% to 66.7% (calculated based on the
longest/shortest molds of the prior art described above) compared
to the molds commonly used in the prior art.
[0028] Through repeated experiments, we have unexpectedly
discovered that the method of the present invention for preparing a
pultruded polyurethane composite by a polyurethane pultrusion
process shortens the length of molds, improves the production
efficiency of the pultrusion process, meanwhile saves raw materials
and manufactures a pultruded polyurethane composite of satisfactory
quality.
[0029] Another aspect of the present invention provides a pultruded
polyurethane composite prepared by a method for preparing a
polyurethane composite by a polyurethane pultrusion process. The
pultruded polyurethane composite is prepared by reaction of a
polyurethane composition comprising the following components:
[0030] a component A, including one or more polyisocyanates; [0031]
a component B, including: [0032] b1) one or more polyols in an
amount of 21 to 60 wt %, preferably 21 to 40 wt %, based on the
total weight of the polyurethane composition as 100 wt %; [0033]
b2) one or more compounds having a structure of formula (I)
[0033] ##STR00002## wherein R1 is selected from the group
consisting of hydrogen, methyl or ethyl; R2 is selected from the
group consisting of an alkylene group having 2 to 6 carbon atoms,
2,2-di(4-phenylene)-propane, 1,4-di(methylene)benzene,
1,3-di(methylene)benzene, 1,2-di(methylene)benzene; n is an integer
selected from 1 to 6; and [0034] a component C, including free
radical initiator.
[0035] Preferably, the polyurethane resin is prepared under a
reaction condition in which the polyurethane composition is
simultaneously subjected to a free radical polymerization reaction
and a polyaddition reaction of isocyanate groups and hydroxyl
groups.
[0036] Preferably, b1) is selected from the group consisting of
organic polyols, wherein said organic polyols have a functionality
of 1.7 to 6, preferably 1.9 to 4.5 and a hydroxyl value of 150 to
1100 mg KOH/g, preferably 150 to 550 mg KOH/g.
[0037] Preferably, b2) is present in an amount of 4.6 to 33 wt %,
based on the total weight of the polyurethane composition as 100 wt
%.
[0038] Preferably, the polyurethane composition has a curing time
of 10 to 120 seconds, preferably 15 to 90 seconds, at 150 to
220.degree. C.
[0039] Preferably, the polyurethane composition has a gel time of
15 to 90 minutes, preferably 20 to 60 minutes, at room
temperature.
[0040] Still another aspect of the present invention provides a
polyurethane product comprising the pultruded polyurethane
composite obtained by the method for preparing a polyurethane
composite by a polyurethane pultrusion process of the present
invention.
[0041] Preferably, the polyurethane product of the present
invention may be selected from the group consisting of cable trays,
curtain wall frames for doors and windows, ladder frames, tent
poles or tubes, anti-glare panels, floors, sucker rods, electric
poles and crossarms, guardrails, grids, profiles for construction,
profiles and plates for container, bicycle frames, fishing rods,
cable cores, insulator core rods, radomes, single or sandwich
continuous plates or spar caps for wind turbine blades.
[0042] The method for preparing a polyurethane composite by a
polyurethane pultrusion process of the present invention employs
the foregoing polyurethane composition, and designs a suitable mold
for it skillfully, and improves the production efficiency of the
pultruded polyurethane composite and saves costs in an appropriate
way. Shorter molds mean smaller weight, especially for larger
products. The reduced weight of molds allows saving a lot of time
for production preparations such as mold maintenance, threading and
heating. At the same time, because the molds are shorter and
lighter, the energy consumption during heating is low, which is
very conducive to energy saving, emission reduction and environment
protection. In addition, due to the shorter molds, not only the
costs for manufacture and maintenance of the molds can be greatly
reduced, but also the loss of raw materials of the polyurethane
composite can be lowered.
[0043] Moreover, the polyurethane composition of the present
invention has a longer gel time and can achieve better polyurethane
pultrusion. The polyurethane composite of the present invention has
excellent physical properties and high glass fiber content.
[0044] In addition, the polyurethane composition of the present
invention has a shorter curing time and a longer gel time, and can
be better and more flexibly suitable for producing pultruded
polyurethane composites, especially large pultruded polyurethane
composites (for example, it can be impregnated and formed for
longer time). Specifically, the fiber reinforcing materials can be
better impregnated and formed for a longer period of time at room
temperature, such as before entering the mold. At high temperature,
such as after entering the mold, it can be cured more quickly.
EMBODIMENTS
[0045] Specific embodiments for carrying out the present invention
are described below.
[0046] According to a first aspect of the present invention, a
method for preparing a pultruded polyurethane composite by a
polyurethane pultrusion process is provided, comprises the steps
of:
[0047] impregnating a fiber reinforcing material with a
polyurethane composition comprising the following components:
[0048] a component A, including one or more organic
polyisocyanates; [0049] a component B, including: [0050] b1) one or
more organic polyols in an amount of 21 to 60 wt %, preferably 21
to 40 wt %, based on the total weight of the polyurethane
composition as 100 wt %; [0051] b2) one or more compounds having a
structure of formula (I)
[0051] ##STR00003## wherein R1 is selected from the group
consisting of hydrogen, methyl or ethyl; R2 is selected from the
group consisting of an alkylene group having 2 to 6 carbon atoms,
2,2-di(4-phenylene)-propane, 1,4-di(methylene)benzene,
1,3-di(methylene)benzene, 1,2-di(methylene)benzene; n is an integer
selected from 1 to 6; and [0052] a component C, free radical
initiator; drawing the impregnated fiber reinforcing material at a
speed of 0.2 to 2 m/min, preferably 0.4 to 1.5 m/min through a mold
having a length of 21 to 55 cm, preferably 25 to 55 cm, more
preferably 30 to 50 cm and a controlled temperature of 110 to
230.degree. C., preferably 150 to 220.degree. C., curing to form
the pultruded polyurethane composite.
[0053] Preferably, the polyurethane resin is prepared under a
reaction condition in which the polyurethane composition is
simultaneously subjected to a free radical polymerization reaction
and a polyaddition reaction of isocyanate groups and hydroxyl
groups.
[0054] Preferably, b1) is selected from the group consisting of
organic polyols, wherein said organic polyols have a functionality
of 1.7 to 6, preferably 1.9 to 4.5 and a hydroxyl value of 150 to
1100 mg KOH/g, preferably 150 to 550 mg KOH/g.
[0055] Preferably, b2) is present in an amount of 4.6 to 33 wt %,
based on the total weight of the polyurethane composition as 100 wt
%.
[0056] Optionally, the reinforcing material is selected from the
group consisting of fiber reinforcing materials, carbon nanotubes,
hard particles, or combinations thereof, more preferably fiber
reinforcing materials. The reinforcing material has a weight
content of 60 to 90 wt %, preferably 75 to 85 wt %, based on the
total weight of the polyurethane composite as 100 wt %.
[0057] When a fiber reinforcing material is used in the present
invention, there is no requirements on its shape and size. For
example, it may be a continuous fiber, a fiber web formed by
bonding, or a fiber fabric.
[0058] In some embodiments of the present invention, the fiber
reinforcing material is selected from the group consisting of glass
fiber, carbon fiber, polyester fiber, natural fiber, aramid fiber,
nylon fiber, basalt fiber, boron fiber, silicon carbide fiber,
asbestos fiber, whisker, metal fiber or combinations thereof.
[0059] Optionally, the organic polyisocyanate can be any aliphatic,
cycloaliphatic or aromatic isocyanate known for use in the
preparation of polyurethanes. Examples thereof include, but are not
limited to, toluene diisocyanate (TDI), diphenylmethane
diisocyanate (MDI), polyphenyl polymethylene polyisocyanate (pMDI),
1,5-naphthalene diisocyanate (NDI), hexamethylene diisocyanate
(HDI), methylcyclohexyl diisocyanate (TDI),
4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate
(IPDI), p-phenylene diisocyanate (PPDI), p-xylene diisocyanate
(XDI), tetramethylxylene diisocyanate (TMXDI), and their multimers
or combinations thereof. The isocyanate useful in the present
invention has preferably a functionality of 2.0 to 3.5,
particularly preferably 2.1 to 2.9. The isocyanate has preferably a
viscosity of 5 to 700 mPas, particularly preferably of 10 to 300
mPas, measured at 25 .degree. C. according to DIN 53019-1-3.
[0060] When used in the present invention, organic polyisocyanates
include isocyanate dimers, trimers, tetramers, pentamers or
combinations thereof.
[0061] In a preferred embodiment of the present invention, the
isocyanate component A is selected from the group consisting of
diphenylmethane diisocyanate (MDI), polyphenyl polymethylene
polyisocyanate (pMDI), and their multimers, prepolymers, or
combinations thereof.
[0062] The blocked isocyanate can also be used as the isocyanate
component A, which can be prepared by reacting an excess of an
organic polyisocyanate or a mixture thereof with a polyol compound.
These compounds and preparation methods thereof are well known to
those skilled in the art.
[0063] The polyurethane composition of the present invention
comprises one or more organic polyols b1). The organic polyol is
present in an amount of from 21 to 60 wt %, based on the total
weight of the polyurethane composition as 100 wt %. The organic
polyol may be an organic polyol commonly used in the art for
preparing polyurethanes, including but not limited to polyether
polyols, polyether carbonate polyols, polyester polyols,
polycarbonate diols, polymeric polyols, vegetable oil-based polyols
or combinations thereof.
[0064] The polyether polyol can be prepared by a known process, for
example, by reacting an olefin oxide with an initiator in the
presence of a catalyst. The catalyst is preferably, but not limited
to, a basic hydroxide, a basic alkoxide, antimony pentachloride,
boron fluoride etherate, or a mixture thereof. The olefin oxide is
preferably, but not limited to, tetrahydrofuran, ethylene oxide,
propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, styrene
oxide, or a mixture thereof, particularly preferably ethylene oxide
and/or propylene oxide. The initiator is preferably, but not
limited to, a polyhydroxy compound or a polyamino compound. Said
polyhydroxy compound is preferably, but not limited to, water,
ethylene glycol, 1,2-propanediol, 1,3-propanediol, diethylene
glycol, trimethylolpropane, glycerol, bisphenol A, bisphenol S or a
mixture thereof. Said polyamino compound is preferably, but not
limited to, ethylene diamine, propylene diamine, butane diamine,
hexane diamine, diethylenetriamine, toluene diamine or a mixture
thereof.
[0065] The polyether carbonate polyols can also be used in the
present invention. They can be prepared by adding carbon dioxide
and an alkylene oxide onto a starter comprising active hydrogen by
using a double metal cyanide catalyst.
[0066] The polyester polyol is obtained by reacting a dicarboxylic
acid or a dicarboxylic acid anhydride with a polyol. Said
dicarboxylic acid is preferably, but not limited to, an aliphatic
carboxylic acid having 2 to 12 carbon atoms. Said aliphatic
carboxylic acid having 2 to 12 carbon atoms is preferably, but not
limited to, succinic acid, malonic acid, glutaric acid, adipic
acid, suberic acid, azelaic acid, sebacic acid, dodecyl carboxylic
acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid,
terephthalic acid, or a mixture thereof. Said dicarboxylic acid
anhydride is preferably, but not limited to, phthalic anhydride,
tetrachlorophthalic anhydride, maleic anhydride, or a mixture
thereof. Said polyol, which is reacted with a dicarboxylic acid or
a dicarboxylic acid anhydride, is preferably but not limited to
ethylene glycol, diethylene glycol, 1,2-propanediol,
1,3-propanediol, dipropylene glycol, 1,3-methyl propylene glycol,
1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol,
1,10-nonanediol, glycerol, trimethylolpropane, or a mixture
thereof. The polyester polyol further includes a polyester polyol
prepared from a lactone. Said polyester polyol prepared from a
lactone is preferably, but not limited to, E-caprolactone.
Preferably, the polyester polyol has a molecular weight of 200 to
3000 and a functionality of 2 to 6, preferably 2 to 5, more
preferably 2 to 4.
[0067] The polycarbonate diol can be prepared by reacting a diol
with a dihydrocarbyl carbonate or a diaryl carbonate or phosgene.
Said diol is preferably, but not limited to, 1,2-propanediol,
1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol,
diethylene glycol, trioxymethylene diol, or a mixture thereof. Said
dihydrocarbyl carbonate or diaryl carbonate is preferably, but not
limited to, diphenyl carbonate.
[0068] The polymeric polyol may be a polymer modified polyether
polyol, preferably a grafted polyether polyol, a polyether polyol
dispersion. Said grafted polyether polyol is preferably a grafted
polyether polyol based on styrene and/or acrylonitrile. Said
styrene and/or acrylonitrile may be obtained by in situ
polymerizing styrene, acrylonitrile, a mixture of styrene and
acrylonitrile. The ratio of styrene to acrylonitrile in the mixture
of styrene and acrylonitrile is 90:10 to 10:90, preferably 70:30 to
30:70. The polymeric polyol of the present invention may also be a
bio-based polyol such as castor oil or wood tar. Said polymeric
polyether polyol dispersion comprises a dispersed phase, for
example, an inorganic filler, a polyurea, a polyhydrazide, a
polyurethane containing a tertiary amino group in a bonded form
and/or melamine. The amount of the dispersed phase is 1 to 50 wt %,
preferably 1 to 45 wt %, based on the weight of the polymeric
polyether polyol as 100 wt %. Preferably, the polymeric polyether
polyol has a polymer solid content of 20% to 45%, based on the
weight of the polymeric polyether as 100%, and a hydroxyl value of
20 to 50 mg KOH/g.
[0069] When used in the present invention, vegetable oil-based
polyols include vegetable oils, vegetable oil polyols or modified
products thereof. Vegetable oils are compounds prepared from an
unsaturated fatty acid and glycerol, or oils extracted from fruits,
seeds and germs of plants, preferably but not limited to peanut
oil, soybean oil, linseed oil, castor oil, rapeseed oil, palm oil.
Said vegetable oil polyol is a polyol starting from one or more
vegetable oils. Starters for synthesing the vegetable oil polyol
include, but are not limited to, soybean oil, palm oil, peanut oil,
rapeseed oil with low erucic acid and castor oil. Hydroxyl groups
can be introduced into the starters of the vegetable oil polyol by
a process such as cracking, oxidation or transesterification.
Hereafter, the corresponding vegetable oil polyols can be prepared
by a process for preparing an organic polyol well known to those
skilled in the art.
[0070] Methods for measuring the hydroxyl value are well known to
those skilled in the art and are disclosed, for example, in Houben
Weyl, Methoden der Organischen Chemie, vol. XIV/2 Makromolekulare
Stoffe, p. 17, Georg Thieme Verlag; Stuttgart 1963. The entire
contents of this document are incorporated herein by reference.
[0071] As used herein, unless otherwise indicated, the
functionality and hydroxyl value of an organic polyol refer to the
average functionality and the average hydroxyl value
respectively.
[0072] Optionally, the polyurethane composition of the present
invention further comprises one or more compounds b2) having a
structure of formula (I)
##STR00004##
wherein R.sub.1 is selected from the group consisting of hydrogen,
methyl or ethyl; R.sub.2 is selected from the group consisting of
an alkylene group having 2 to 6 carbon atoms; and n is an integer
selected from 1 to 6.
[0073] In a preferred embodiment of the present invention, R2 is
selected from the group consisting of ethylene, propylene,
butylene, pentylene, 1-methyl-1,2-ethylene, 2-methyl-1,2-ethylene,
1-ethyl-1,2-ethylene, 2-ethyl-1,2-ethylene, 1-methyl-1,3
-propylene, 2-methyl-1,3-propylene, 3-methyl-1,3-propylene,
1-ethyl-1,3-propylene, 2-ethyl-1,3-propylene, 3-ethyl-1,3
-propylene, 1-methyl-1,4-butylene, 2-methyl-1,4-butylene,
3-methyl-1,4-butylene and 4-methyl-1,4-butylene,
2,2-di(4-phenylene)-propane, 1,4-dimethylenebenzene,
1,3-dimethylenebenzene, 1,2-dimethylenebenzene.
[0074] Preferably, 1) is selected from the group consisting of
organic polyols, wherein said organic polyols have a functionality
of 1.7 to 6, preferably 1.9 to 4.5 and a hydroxyl value of 150 to
1100 mg KOH/g, preferably 150 to 550 mg KOH/g.
[0075] In a preferred embodiment of the present invention, the
component b2) is selected from the group consisting of hydroxyethyl
methacrylate, hydroxypropyl methacrylate, hydroxybutyl
methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate,
hydroxybutyl acrylate or combinations thereof.
[0076] The compound of formula (I) can be prepared by a method
generally used in the art, for example, by esterification reaction
of (meth)acrylic anhydride or (meth)acrylic acid, (meth)acryloyl
halide compound with HO--(R.sub.2O).sub.n--H. The preparation
methods are well known to those skilled in the art, for example, in
"Handbook of Polyurethane Raw Materials and Auxiliaries" (Liu
Yijun, published on Apr. 1, 2005), Chapter 3; "Polyurethane
Elastomer" (Liu Houzhen, published in August 2012), Chapter 2, the
entire contents of which are incorporated herein by reference.
[0077] The polyurethane composition of the present invention
further comprises C, free radical reaction initiator. The free
radical initiator used in the present invention may be added to the
polyol component or the isocyanate component or both components.
Said initiator includes, but is not limited to, a peroxide, a
persulfide, a peroxycarbonate, a peroxyboric acid, an azo compound,
or other suitable free radical initiators that can initiate curing
of double bond-containing compounds. Examples thereof include
tert-butyl peroxy-isopropylcarbonate, tert-butyl
peroxy-3,5,5-trimethylhexanoate, methyl ethyl ketone peroxide, and
cumyl hydroperoxide. Preferably, the free radical reaction
initiator of the present invention is present in an amount of 0.1
to 8 wt %, based on the total weight of the polyurethane
composition of the present invention as 100 wt %. In addition, an
accelerator such as a cobalt compound or an amine compound may also
be present.
[0078] Optionally, the polyurethane composition may also comprise a
catalyst for catalyzing the reaction of isocyanate groups (NCO)
with hydroxyl groups (OH). Suitable catalysts for the polyurethane
reaction are preferably, but not limited to, amine catalysts,
organometallic catalysts, or mixtures thereof. Said amine catalyst
is preferably, but not limited to, triethylamine, tributylamine,
triethylenediamine, N-ethylmorpholine,
N,N,N',N'-tetramethyl-ethylenediamine,
pentamethyldiethylenetriamine, N,N-methylaniline,
N,N-dimethylaniline, or a mixture thereof. Said organometallic
catalyst is preferably, but not limited to, an organotin compound
such as tin (II) acetate, tin (II) octoate, tin ethylhexanoate, tin
laurate, dibutyl tin oxide, dibutyl tin dichloride, dibutyl tin
diacetate, dibutyl tin maleate, dioctyl tin diacetate, or a mixture
thereof. Preferably, said catalyst is used in an amount of 0.001 to
10 wt %, based on the total weight of the polyurethane composition
of the present invention as 100 wt %.
[0079] In an embodiment of the present invention, in the
polyaddition reaction of isocyanate groups and hydroxyl groups, the
isocyanate groups may be those present in the organic
polyisocyanate (component A), or may also be those present in the
reaction intermediate of the organic polyisocyanate (component A)
with the organic polyol (component b1)) or the component b2). The
hydroxyl groups may be those present in the organic polyol
(component 1)1)) or the component b2), or may also be those present
in the reaction intermediate of the organic polyisocyanate
(component A) with the organic polyol (component b1)) or the
component b2).
[0080] In an embodiment of the present invention, the free radical
polymerization reaction is a polyaddition reaction of olefinic
bonds, wherein the olefinic bonds may be those present in the
component b2) or may also be those present in the reaction
intermediate of component b2) with the organic polyisocyanate.
[0081] In an embodiment of the present invention, the polyurethane
polyaddition reaction (i.e., the polyaddition reaction of
isocyanate groups and hydroxyl groups) is carried out
simultaneously with the free radical polymerization reaction. It is
well known to those skilled in the art that suitable reaction
conditions can be selected so that the polyurethane polyaddition
reaction and the free radical polymerization reaction are carried
out successively. However, the polyurethane matrix thus obtained
and the polyurethane resin matrix obtained in a method in which the
polyurethane polyaddition reaction and the free radical
polymerization reaction are simultaneously carried out are
different in terms of the structure. Therefore, the prepared
polyurethane composites are different in terms of mechanical
properties and processability.
[0082] Optionally, the above polyurethane composition may further
comprise an auxiliary or an additive, including but not limited to
a filler, an internal mold releasing agent, a flame retardant, a
smoke suppressant, a dye, a pigment, an antistatic agent, an
antioxidant, a UV stabilization, a diluent, a defoaming agent, a
coupling agent, a surface wetting agent, a leveling agent, a water
scavenger, a catalyst, a molecular sieve, a thixotropic agent, a
plasticizer, a foaming agent, a foam stabilizer, a foam
homogenizing agent, an inhibitor for free radical reaction or a
combination thereof. These components may optionally be included in
the isocyanate component A) and/or the polyurethane composition B)
of the present invention. These components may also be stored
separately as a component D), which is mixed with the isocyanate
component A) and/or the polyurethane composition B) of the present
invention and then used for the preparation of polyurethane
composites.
[0083] In some embodiments of the present invention, the filler is
selected from the group consisting of aluminum hydroxide,
bentonite, pulverous coal, wollastonite, perlite powder, floating
bead, calcium carbonate, talcum powder, mica powder, china clay,
fumed silica, expandable microsphere, diatomaceous earth, volcanic
ash, barium sulfate, calcium sulfate, glass microsphere, stone
powder, wood powder, wood chips, bamboo powder, bamboo chips, rice
grains, straw chips, sorghum stalk chips, graphite powder, metal
powder, recycled powder of thermoset composite, plastic granules or
powder or a combination thereof. Said glass microsphere may be
solid or hollow.
[0084] The internal mold releasing agent which can be used in the
present invention includes any conventional mold releasing agent
for producing polyurethanes. Examples thereof include long-chain
carboxylic acids, especially fatty acids such as stearic acid,
amines of long-chain carboxylic acids such as stearamide, fatty
acid esters, metal salts of long-chain carboxylic acids such as
zinc stearate, or polysiloxane.
[0085] Examples of the flame retardant which can be used in the
present invention include triaryl phosphate, trialkyl phosphate,
halogen-containing triaryl phosphate or trialkyl phosphate,
melamine, melamine resin, halogenated paraffin, red phosphorus or
combinations thereof.
[0086] Other auxiliaries which can be used in the present invention
include a water scavenger such as a molecular sieve; a defoaming
agent such as polydimethylsiloxane; a coupling agent such as
monoethylene oxide or organoamine functionalized trialkoxysilane or
combinations thereof. The coupling agent is particularly preferably
used to increase the adhesion of the resin matrix to the fiber
reinforcing materials. Fine particulate fillers, such as clay and
fumed silica, are often used as the thixotropic agent.
[0087] The inhibitor for free radical reaction which can be used in
the present invention includes a polymerization inhibitor and a
polymerization retarder, and the like, for example, certain
phenols, quinone compounds or hindered amine compounds. Examples
thereof include methyl hydroquinone, p-methoxyphenol, benzoquinone,
polymethyl pyridine derivatives, copper ions with low valence
state, and the like.
[0088] Preferably, the polyurethane composition of the present
invention has a curing time of 10 to 120 seconds, preferably 15 to
90 seconds, at 150 to 220.degree. C.
[0089] Preferably, the polyurethane composition of the present
invention has a gel time of 15 to 90 minutes, preferably 20 to 60
minutes at room temperature. In general, the term "gel time" means
a period of time that begins when the component A and the component
B of the reaction system start to mix and ends when the viscosity
reaches a certain value (for example, about 10000 mPas). The gel
time mentioned in the embodiments of the present invention is
measured using a gel time tester.
[0090] Preferably, the impregnating of the present invention is
carried out in an impregnation device comprising an injection box
and an open impregnation tank.
[0091] Preferably, the injection pressure in the injection box is
0.1 to 15 bar, preferably 0.1 to 10 bar.
[0092] As described above, the molds of polyurethane compositions
(without the component b2) of the present invention and the
component free radical initiator) which is conventionally used in
the pultrusion process in the prior art has a length generally from
90 to 100 cm. The molds of the present invention can be shortened
by 45% to 76.7%, preferably 45% to 72.2%, more preferably 50% to
66.7% (calculated based on the longest/shortest molds of the prior
art described above) compared to the molds commonly used in the
prior art.
[0093] Through repeated experiments, we have unexpectedly
discovered that the method for preparing a pultruded polyurethane
composite by a polyurethane pultrusion process of the present
invention shortens the length of the molds, improves the production
efficiency of the pultrusion process, meanwhile saves raw materials
and manufactures a pultruded polyurethane composite of satisfactory
quality.
[0094] In addition, the polyurethane composition of the present
invention has a shorter curing time and a longer gel time, and can
be better and more flexibly suitable for producing pultruded
polyurethane composites, especially large pultruded polyurethane
composites (for example, it can be impregnated and formed for
longer time). Specifically, the fiber reinforcing materials can be
better impregnated and formed for a longer period of time at room
temperature, such as before entering the mold. At high temperature,
such as after entering the mold, it can be cured more quickly.
[0095] Another aspect of the present invention provides a pultruded
polyurethane composite obtained by a method for preparing a
polyurethane composite by a polyurethane pultrusion process. The
pultruded polyurethane composite is prepared by reaction of a
polyurethane composition comprising the following components:
[0096] a component A, including one or more organic
polyisocyanates; [0097] a component B, including: [0098] b1) one or
more organic polyols in an amount of 21 to 60 wt %, preferably 21
to 40 wt %, based on the total weight of the polyurethane
composition as 100 wt %; [0099] b2) one or more compounds having a
structure of formula (I)
[0099] ##STR00005## wherein R1 is selected from the group
consisting of hydrogen, methyl or ethyl; R2 is selected from the
group consisting of an alkylene group having 2 to 6 carbon atoms,
2,2-di(4-phenylene)-propane, 1,4-di(methylene)benzene,
1,3-di(methylene)benzene, 1,2-di(methylene)benzene; n is an integer
selected from 1 to 6; and [0100] a component C, free radical
initiator.
[0101] Preferably, the polyurethane resin is prepared under a
reaction condition in which the polyurethane composition is
simultaneously subjected to a free radical polymerization reaction
and a polyaddition reaction of isocyanate groups and hydroxyl
groups.
[0102] Preferably, b1) is selected from the group consisting of
organic polyols, wherein said organic polyols have a functionality
of 1.7 to 6, preferably 1.9 to 4.5 and a hydroxyl value of 150 to
1100 mg KOH/g, preferably 150 to 550 mg KOH/g.
[0103] Preferably, b2) is present in an amount of 4.6 to 33 wt %,
based on the total weight of the polyurethane composition as 100 wt
%.
[0104] Preferably, the polyurethane composition has a curing time
of 10 to 120 seconds, preferably 15 to 90 seconds, at 150 to
220.degree. C.
[0105] Preferably, the polyurethane composition has a gel time of
15 to 90 minutes, preferably 20 to 60 minutes, at room
temperature.
[0106] Still another aspect of the invention provides a
polyurethane product. The polyurethane product comprises the
pultruded polyurethane composite obtained by the method for
preparing a polyurethane composite by a polyurethane pultrusion
process of the present invention.
[0107] Preferably, the polyurethane product of the present
invention may be selected from the group consisting of cable trays,
curtain wall frames for doors and windows, ladder frames, tent
poles or tubes, anti-glare panels, floors, sucker rods, electric
poles and crossarms, guardrails, grids, profiles for construction,
profiles and plates for container, bicycle frames, fishing rods,
cable cores, insulator core rods, radomes, single or sandwich
continuous plates or spar caps for wind turbine blades.
[0108] Unless defined otherwise, all technical and scientific terms
used herein have the same meaning as they are generally understood
by those skilled in the art of the present invention. When
definitions of the terms in this specification conflicts with the
meaning generally understood by those skilled in the art of the
present invention, the definitions described herein shall
prevail.
[0109] The invention is exemplified by the following examples.
However, it should be understood that the scope of the invention is
not limited by these examples.
DESCRIPTION OF DRAWINGS
[0110] The invention will be exemplarily described below with
reference to the drawings:
[0111] FIG. 1 shows a mold and a process flow for the method for
preparing a pultruded polyurethane composite by a pultrusion
process according to an embodiment of the present invention,
wherein: 1 and 2 represent fibers; 3 represents a yarn guiding
device; 4 represents an impregnation device; 5 represents a mold; 6
represents a profile; 7 represents a drawing device; 8 and 9
represent a heating device.
EXAMPLES
[0112] Description of tested performance parameters in the examples
of the present application:
[0113] Functionality refers to a value determined according to the
formula in the industry: functionality=hydroxyl value*molecular
weight/56100; wherein the molecular weight is determined by GPC
high performance liquid chromatography;
[0114] Isocyanate index refers to a value determined by the
following formula:
Isocyanateindex .function. ( % ) = Molesofisocyanategroups .times.
.times. ( NCOgroups ) .times. incomponentA
MolesofgroupsreactivetowardisocyanategroupsincomponentB .times. d
##EQU00001##
[0115] NCO content refers to the content of NCO groups in the
system and is measured according to GB/T 12009.4-2016.
[0116] Pultrusion rate/speed, i.e. the speed at which the fiber
reinforceing materials are drawn through the mold, refers to the
length of the fiber reinforcing materials pultruded through the
mold per minute, i.e. the length of the pultruded product produced
per minute. In the test, a speed sensor or a stopwatch and a ruler
are used. The pultrusion rate/speed, i.e. the length passing
through the mold per unit time, is obtained as the measured length
of the pultruded fiber reinforcing materials divided by the time
used.
[0117] Curing time refers to a period of time that begins when the
component A and the component B of the reaction system start to mix
and ends when it is cured.
[0118] Gel time refers to a period of time that begins when the
component A and the component B of the reaction system start to mix
and ends when the viscosity reaches a certain value (for example,
about 10000 mPas). The gel time of the present invention is tested
using a gel time tester. In the test, the component A and the
component B are mixed uniformly and then placed in the gel time
tester. The gel time is recorded as a period of time that begins
when the power button is pressed and ends when the gel time tester
stops working.
Source of Raw Materials and Description Thereof
TABLE-US-00001 [0119] TABLE 1 List of raw materials Material/device
Specification/type Supplier Isocyanate 1 Desmodur1511L Covestro
Polymers (China) Co., Ltd. Isocyanate 2 Desmodur 0223 Covestro
Polymers (with free radical (China) Co., Ltd. initiator) Polyol
Baydur 18BD001 Covestro Polymers composition 1 (without component
(China) Co., Ltd. b2)) Polyol Baydur 18BD207 Covestro Polymers
composition 2 (with component (China) Co., Ltd. b2)) Internal mold
Baydur 18BD101 Covestro Polymers releasing agent (China) Co., Ltd.
Glass fiber PS 4100-2400Tex Owens Corning Composites (China) Co.,
Ltd. Pultrusion Crawler pultrusion Nanjing Nuoertai machine machine
for Compound composites Materials Equipment Manufacturing Co., Ltd.
Injection device Hydraulic Mini Magnum Venus Products Link System
Gel time tester GT-STHP-220 Shanghai Senlan Scientific Instrument
Co., Ltd.
Example 1
[0120] As shown in FIG. 1, 240 bundles of glass fibers were taken
out from the creel and passed sequentially through the preformed
plates into the injection box and the mold (length of the mold was
40 cm). Then, the glass fibers were drawn forward by the drawing
device until they were straightened. The heating device of the mold
was turned on. The mold temperature was set at the inlet and the
outlet to 120.degree. C./220.degree. C. After the temperature was
stable, the injection device was turned on. The component A
(Desmodur 0223) and the component B (100 parts by weight of Baydur
18BD207 and 3 parts by weight of Baydur 18BD101) were continuously
pumped by the injection device into the static mixing head of the
injection box in a weight ratio of 92:100. The injection box was
fully filled with the components after they were mixed by the
static mixing head. The glass fibers were fully impregnated. The
injection pressure in the injection box was set to 0.1 to 15 bar.
The glass fibers impregnated by the injection box was continuously
pulled by the drawing device through the mold at a speed of 0.4
m/min to obtain a pultruded polyurethane composite. When the
pultruded polyurethane composite was knocked using a metal piece at
1 m from the outlet of the mold, the sound was clear, indicating
that the curing was well.
[0121] The polyurethane composition of Example 1 had a cure time of
about 40 seconds and a gel time of 40 minutes.
Comparative Example 1
[0122] As shown in FIG. 1, 240 bundles of glass fibers were taken
out from the creel and passed sequentially through the preformed
plates into the injection box and the mold (length of the mold was
40 cm). Then, the glass fibers were drawn forward by the drawing
device until they were straightened. The heating device of the mold
was turned on. The mold temperature was set at the inlet and the
outlet to 120.degree. C./190.degree. C. After the temperature was
stable, the injection device was turned on. The component A
(Desmodur 1511L) and the component B (100 parts of Baydur 18BD001
and 5 parts of Baydurl8BD101) were continuously pumped by the
injection device into the static mixing head in a weight ratio of
114:100. The injection box was fully filled with the components,
after they were mixed by the static mixing head. The fiber yarns
were fully impregnated. The injection pressure in the injection box
was set to 0.1 to 15 bar. The fiber yarns impregnated by the
injection box was continuously pulled by the drawing device through
the mold at a speed of 0.4 m/min. When the profile was knocked
using a metal piece at 1 m from the outlet of the mold, the sound
was dull, indicating that the curing was poor.
[0123] The polyurethane composition of Comparative Example 1 had a
cure time of about 70 seconds and a gel time of about 23
minutes.
[0124] It can be seen from the experimental results of Example 1
and Comparative Example 1 as above that the method for preparing a
pultruded polyurethane composite using a suitable mold and a
corresponding polyurethane composition of the present invention
allows producing a well-cured pultruded polyurethane composite. The
use of short molds improves the production efficiency, saves costs
and energy and protects the environment. When the same mold was
used, pultrusion of a polyurethane composition without the
component b2) in the prior art could not provide a well-cured
pultruded composite. In addition, the polyurethane composition of
the present invention has a shorter curing time and a longer gel
time, and can be better and more flexibly suitable for producing
polyurethane composites, especially large polyurethane composites
(for example, it can be impregnated and formed for longer
time).
[0125] While the invention has been described in detail as above
for the purposes of the present invention, it is understood that
the detailed description is only exemplary. In addition to the
contents defined by the claims, various changes can be made by
those skilled in the art without departing from the spirit and
scope of the invention.
* * * * *